Lock for telescoping members.



G. G. SGHOENBORN.

LOOK FOR TELESOOPING MEMBERS.

APPLIUATION FILED NOV. 24, 1913.

1,094,1 69, Patented Apr. .21, 1914.

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GUSTAV c. sononnnonn, or nnrnorr, MICHIGAN.

LOCK FOR TELESGOPING MEMBERS.

Specification of Letters Patent.

Patented Apr. 21, 1914.

Application filed November 24, 1913. Serial No. 802,643.

To all whom it may concern: I

Be it known that I, GUSTAV C. Sorronn- BORN, a citizen of the United States, residing at Detroit, county of Wayne, State of Michigan, have invented a certain new and useful Improvement in Looks for Telescoping Members, and declare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification.

This invention relates to adjustable locks for telescoping members and especially to a lock for an adjustable hack saw frame.

In the drawings Figure 1, is an elevation of the hack saw, part of the handle being in section. Fig. 2, is an elevation of the telescoping frame parts and the look, a portion of the parts being broken away in section, Fig. 3, is an elevation of the telescoping frame parts and the look, a portion of the parts being broken away and sectioned. This elevation is taken a quarter of a turn about the frame parts from the position shown in Fig. 2. Fig. 4, is a similar view to that shown in Fig. 3, except that the lock is in position of release. Fig. 5, is a sectional detail taken on the line A-A of Fig. 1.

The customary yoke form of hack saw is made up of two telescoping parts a and b. b has a key way 0 and a carries a loose key 0? that protrudes into the key way thereby keeping the two parts a and b from turning with respect to each other. The tube a is provided with a perforation 6 while the slide Z) has as many hemispherical recesses f as there are positions of adjustment desired. Along the slide Z) are marks 9 which indicate that when the end of the tube a coincides with the mark the perforation 6 will register with one of the recesses f. A ball it is confined by a thimble i that has an annular groove j on its inner side. Fig. 3 shows the ball A both in one of the recesses and in the perforation e, The thimble i fits tightly over it and prevents it from being forced out. In this position a pull on either or both of the parts a and b not only fails to dislodge the ball but fails to produce any separating movement between the two,

as the ball h ties them securely together.

When it is desired to change the position of adjustment the thimble i is shifted to end of the sleeve.

with the ball and a pull on the frame part or slide Z2 causes the ball to be projected outward into the cavity formed by the perforation e and the annular groove j. This allows relative movement of the parts a and 7) with comparative freedom. When the mark g, indicating the adjustment for a saw of a given length is reached, the ball will againdrop into one of the recesses f and the thimble may be pushed back to the right to lock it in place. The removable pin a prevents the thimble being accidentally slipped off this outer telescoping member.

This locking device is especially adapted for a hack saw frame as it cooperates with the tightening device of the saw to prevent the telescoping members being accidentally unlocked, as will appear when I have de scribed the tightening device and the saw holders. The saw is carried upon two holders, one designated 17?. which has a frictional fit in the sleeve that terminates the frame part or tube a and the other designated a and slidable through the sleeve which terminates the frame part or slide 6. A saw 0 has perforations at each end that fit over the studs 29 of the holders. The washer g is provided with a pair of keys 1 raised on one surface and these can be fitted into one set of two or more sets of grooves s in the outer This allows the adjustment of the holder 91. by turning that member a quarter of a turn, or any portion of a turn determined by the location of the grooves. Similar keys and grooves u in the holder m and the sleeve terminating the part of tube a permit the similar adjustment of the holder at. These devices allow angular adjustment of the saw 0 with respect to the frame. It often becomes necessary to change this angular relation of the saw with respect to the frame, due to the crowded environment in which the saw must be used. The washer g is prevented from turning upon the screwthreaded stem (Z of the holder at by reason of the flattened portion shown in Fig. 5. The handle 10 has a threaded interior w, hence by unscrewing the handle, the holder a may be released so that the saw 0 may be lifted off from the studs. However, it is one of the features of this invention that up until the time the handle to is unscrewed to release the holder at it is not possible to thrust the thimble i to the right against the stud k, be

cause of the fact that the tension between the sleeves a and 1" tends to draw the telescoping parts and b slightly out of line. (See l ig. 3.) Inasmuch as the ball is always located on the outside of the frame it is influenced by this cocking of the part or slide 5, so that it binds firmly against the thimble i and this member can not, with any ordinary force, be moved. However, as soon as the handle a is unscrewed the binding influence is removed and it is possible to slide the thimble to the left to release the frame parts. Of course to effect this binding action there must be a slightly loose fit between the slide Z) and the tube a.

It will be noted that the thimble i is always over the key 03. Hence this member may be a loose key which will always be confined in the key until the thimble is taken off.

What I claim is:

1. The combination of a pair of telescoping members, the inner one being provided with a key way, the outer one being provided with a loose key that fits into the key way, the inner member being also provided with a plurality of recesses, the outer member being also provided with a perforation, a ball for engaging in a recess and the perforation when the same register, and a thimble provided with a recess for engaging over the loose key and over the ball to hold the former in place and hold the latter from being forced out of the recess in which it rests until the thimble is moved to allow the ball to withdraw into the recess of the thimble, substantially as described.

2. The combination of a pair of telescoping frame parts held in non-rotative relation and forming a yoke, a linear member connecting the frame ends, means for tightenring the linear member with respect to the frame members, the said inner frame memher being provided with a plurality of recesses, the said outer frame member being provided with a perforation and ball engaging in the perforation and a registering recess, and a thimble adapted to he slipped over the ball to hold the same in place, the said thimble being held firmly over the ball when the tightening means causes the two telescoping members to be tipped slightly out of alinement.

3. The combination of a pair of telescoping frame parts being curved to form a yoke, a linear member connecting the yoke ends, means for tightening the linear memher with respect to the frame parts, the inner frame member being provided with a plurality of recesses, the outer frame member being provided with a perforation, a ball engaging in the perforation and a registering recess, and a thimble slidable over the outside telescoping part and the ball to hold the ball in place, the said thimble being provided with a recess and being movable for a given distance along said outer telescoping part, to either hold the ball in place or allow it to withdraw into the recess, the said telescoping members being adapted to be slightly cocked. with respect to each other when the linear member is tightened with respect to the frame members, thereby tightening the ball with respect to the thimble so that same can not be moved.

In testimony whereof, I sign this specification in the presence of two witnesses.

GUSTAV C. SCHOENBORN.

Witnesses:

STUART C. BARNES, MARIETTA E. RUDD.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents.

Washington, I). C. 

